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| author | Alex Elder <elder@dreamhost.com> | 2012-03-07 11:40:08 -0600 |
|---|---|---|
| committer | Alex Elder <elder@dreamhost.com> | 2012-03-22 10:47:52 -0500 |
| commit | 8d63e318c4eb1bea6f7e3cb4b77849eaa167bfec (patch) | |
| tree | 4783d4d0ab9a5d9c17e8eb0f93b0d279ad1b879a /net | |
| parent | 9bd1966344bf975b5ce65e80fd6bacc41b4325a8 (diff) | |
| download | lwn-8d63e318c4eb1bea6f7e3cb4b77849eaa167bfec.tar.gz lwn-8d63e318c4eb1bea6f7e3cb4b77849eaa167bfec.zip | |
libceph: isolate kmap() call in write_partial_msg_pages()
In write_partial_msg_pages(), every case now does an identical call
to kmap(page). Instead, just call it once inside the CRC-computing
block where it's needed. Move the definition of kaddr inside that
block, and make it a (char *) to ensure portable pointer arithmetic.
We still don't kunmap() it until after the sendpage() call, in case
that also ends up needing to use the mapping.
Signed-off-by: Alex Elder <elder@dreamhost.com>
Reviewed-by: Sage Weil <sage@newdream.net>
Diffstat (limited to 'net')
| -rw-r--r-- | net/ceph/messenger.c | 13 |
1 files changed, 2 insertions, 11 deletions
diff --git a/net/ceph/messenger.c b/net/ceph/messenger.c index 2bf9ab4429e6..f0993af2ae4d 100644 --- a/net/ceph/messenger.c +++ b/net/ceph/messenger.c @@ -835,7 +835,6 @@ static int write_partial_msg_pages(struct ceph_connection *con) while (data_len > con->out_msg_pos.data_pos) { struct page *page = NULL; - void *kaddr = NULL; int max_write = PAGE_SIZE; int bio_offset = 0; @@ -856,18 +855,12 @@ static int write_partial_msg_pages(struct ceph_connection *con) page = list_first_entry(&msg->trail->head, struct page, lru); - if (do_datacrc) - kaddr = kmap(page); max_write = PAGE_SIZE; } else if (msg->pages) { page = msg->pages[con->out_msg_pos.page]; - if (do_datacrc) - kaddr = kmap(page); } else if (msg->pagelist) { page = list_first_entry(&msg->pagelist->head, struct page, lru); - if (do_datacrc) - kaddr = kmap(page); #ifdef CONFIG_BLOCK } else if (msg->bio) { struct bio_vec *bv; @@ -875,14 +868,10 @@ static int write_partial_msg_pages(struct ceph_connection *con) bv = bio_iovec_idx(msg->bio_iter, msg->bio_seg); page = bv->bv_page; bio_offset = bv->bv_offset; - if (do_datacrc) - kaddr = kmap(page); max_write = bv->bv_len; #endif } else { page = zero_page; - if (do_datacrc) - kaddr = kmap(page); } len = min_t(int, max_write - con->out_msg_pos.page_pos, total_max_write); @@ -891,7 +880,9 @@ static int write_partial_msg_pages(struct ceph_connection *con) void *base; u32 crc; u32 tmpcrc = le32_to_cpu(con->out_msg->footer.data_crc); + char *kaddr; + kaddr = kmap(page); BUG_ON(kaddr == NULL); base = kaddr + con->out_msg_pos.page_pos + bio_offset; crc = crc32c(tmpcrc, base, len); |